HIROSHIMA – — Radiation levels on deserted Rongelap Island near the former U.S. nuclear test site on Bikini Atoll in the Pacific have dropped to levels safe for human habitation, according to a study by a Japanese researcher.
Jun Takada, of Hiroshima University’s Research Institute for Radiation Biology and Medicine, announced this week that his research in 1999 showed levels of radiation on the island were lower than those in Tokyo and Hiroshima.
Measurements showed the annual level of radiation was around 0.2 millisievert, lower than the maximum of 1 millisievert set by the Stockholm-based International Commission on Radiological Protection, Takada said.
The United States exploded a hydrogen bomb at the atoll on March 1, 1954, 200 km east of Rongelap Island, exposing islanders to high levels of radiation.
The islanders were evacuated to neighboring islands soon after the test but returned three years later. They left again in 1985 after radiation-linked illnesses were reported, but around 400 islanders still hope to return.
Takada said his research also showed that cesium 137 in the soil was at an acceptable level of 26 kilobecquerel per sq. meter.
“If I were a Rongelap islander, I would return home with my family,” he said.
Takada conducted research at 17 locations on the island in July 1999 and discovered that alpha, beta and gamma rays all fell below levels found in central Tokyo and Hiroshima.
Takada, an associate professor of the institute, is known for his research into radiation levels around the Chernobyl nuclear plant in Ukraine, the site of the world’s worst nuclear accident in 1986.
He has also probed radiation levels around the former Semipalatinsk nuclear test site in Kazakstan, where the Soviet Union has reportedly conducted nearly 500 nuclear tests since 1949.
At the time of the 1954 test, the Japanese tuna fishing boat Fukuryu Maru (Lucky Dragon) No. 5 was operating in waters about 50 km northwest of Rongelap Island, and the 23 crew members were affected by fallout.
One of the 23, Aikichi Kuboyama, died six months later of radiation-linked causes, and is believed to be the first Japanese victim of a U.S. nuclear explosion since the 1945 atomic bombings of Hiroshima and Nagasaki.